21648653 has 8 divisors (see below), whose sum is σ = 23521848. Its totient is φ = 19805184.

The previous prime is 21648647. The next prime is 21648673. The reversal of 21648653 is 35684612.

It can be written as a sum of positive squares in 4 ways, for example, as 91204 + 21557449 = 302^2 + 4643^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21648653 - 2¹⁰ = 21647629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21648673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5900 + ... + 8837.

It is an arithmetic number, because the mean of its divisors is an integer number (2940231).

Almost surely, 2^21648653 is an apocalyptic number.

It is an amenable number.

21648653 is a deficient number, since it is larger than the sum of its proper divisors (1873195).

21648653 is a wasteful number, since it uses less digits than its factorization.

21648653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14863.

The product of its digits is 34560, while the sum is 35.

The square root of 21648653 is about 4652.8113007084. The cubic root of 21648653 is about 278.7042724966.

The spelling of 21648653 in words is "twenty-one million, six hundred forty-eight thousand, six hundred fifty-three".